--- a/source3/printing/samba-bgqd.c
+++ b/source3/printing/samba-bgqd.c
@@ -42,6 +42,8 @@
 #include "source3/printing/queue_process.h"
 #include "source3/lib/substitute.h"
 
+#include <signal.h>
+
 static void watch_handler(struct tevent_req *req)
 {
 	bool *pdone = tevent_req_callback_data_void(req);
